This invention relates to systems of lock-out/tag-out (LOTO) to protect technicians providing maintenance and monitoring of equipment. Lock-out/tag-out systems can give notice to technicians of the status of equipment and/or prevent access to hazardous environments.
Before performing monitoring, maintenance or repair of electronic or mechanical equipment, a safe environment must be provided for the technician. Safety can be provided by hazard labels, status indicators, identity labels and locks. Safety can be enhanced by redundant lock-out and/or tag-out systems.
Hazard labels are a common form of reducing hazards to technicians. Many new products provide notice to users on ways to avoid harm to themselves and the appliance in the owners manual. Hazard warning labels are often present on access panels to warn technicians of voltage and mechanical danger. Such panels can be linked, as a safety feature, to the equipment power source to shut off power if the panel is opened.
Tag out systems can provide notice of danger and indicate requirements for access to work areas. A brightly colored tag can be attached to the latch of an access door to, e.g., warn of the internal hazards, indicate the proper procedure for safe entry, and/or to inform a technician of compliance documentation requirements for entry.
Lock out systems can prevent unauthorized individuals from gaining entry to hazardous areas. Access doors to hazardous work areas and equipment can be secured with a lock with the key or code available only to properly trained technicians. In this way, uninformed technicians can not casually enter a hazardous work environment. More sophisticated lock out systems can include safety confirmation by a computer or manager before technician entry is allowed. For example, a manager in a control room can remotely control the lock to a door in a hazard area. The manager can confirm the inactivation of hazards before allowing entry of the technician.
Another way to provide an element of safety to technicians in hazardous work environments is through scheduling systems. For example, a master schedule of equipment inactivation can be established so the technician and other workers at remote locations know what equipment is to be inactivated at what time and date. However, when the technician works over the scheduled inactivation time or if a remote worker fails to review the schedule, the equipment can be activated while the technician is still in danger.
Fail safe systems can be incorporated into technician safety systems. For example, in U.S. Pat. No. 6,268,574, “Electrical and Pneumatic Lock-Out Device”, to Edens, a lock out device is incorporated into access doors to hazardous areas whereby power can not be supplied to equipment when the door to the work area is opened. In another example, U.S. Pat. No. 4,911,198, “Securing System for Automatically Operated Valve Systems”, to Kerin, a locking clip is provided for a technician to override any remote activation signal to equipment in a hazardous work area.
A need remains for additional ways to ensure the safety of technicians. For example, a way to evaluate equipment identification, technician identification, scheduling and equipment status before and during maintenance procedures can help prevent accidents. The present invention provides these and other features which will be apparent upon complete review of the following.